Urinary carnitine excretion in patients with heart failure

Area of Science:

• Biochemistry
• Cardiology
• Metabolic Disorders

Background:

• Fatty acid metabolism is crucial for cardiac energy production.
• Heart failure is associated with altered energy substrate utilization.
• Carnitine plays a vital role in transporting fatty acids into mitochondria for beta-oxidation.

Purpose of the Study:

• To investigate urinary free carnitine and acylcarnitine levels in patients with heart failure.
• To explore potential links between carnitine excretion and heart failure severity.
• To assess fatty acid metabolism abnormalities in heart failure.

Main Methods:

• Semiquantitative analysis of urinary free carnitine and acylcarnitine using fast atom bombardment mass spectrometry (FABMS).
• Comparison between 22 heart failure patients and 19 age-matched healthy controls.
• Classification of heart failure patients into high and low urinary free carnitine excretion groups.

Main Results:

• Urinary free carnitine excretion was significantly higher in heart failure patients compared to controls (1.32 vs. 0.20 ratio/mg creatinine, p < 0.01).
• Patients with severe heart failure (NYHA class IV) showed higher urinary free carnitine levels, particularly in the high excretion group.
• No significant abnormalities in urinary organic acid profiles were observed, but increased urinary acetylcarnitine was noted in the high excretion group.

Conclusions:

• Elevated urinary free carnitine excretion is observed in heart failure patients.
• Severe heart failure may be associated with increased carnitine turnover and potential carnitine deficiency.
• Further investigation is warranted to confirm carnitine deficiency and its impact on fatty acid metabolism in heart failure.